Opposite Day
by arainymonday
Summary: Either it's opposite day or something happened overnight to swap their personalities.


**Title:** Opposite Day **  
Rating:** PG-13 **  
Warnings:** none **  
Pairings:** Barry/Len **  
Spoilers:** none

 **Author's Note:** This story was written for qkind on Tumblr. I know nothing about chemistry. I apologize for any atrocious errors.

* * *

 **Opposite Day**

Cisco's eyes shift between Barry and Len suspiciously. "You two are acting weird."

"What do you mean?" Len asks. He fidgets under Cisco's gaze. "We're not acting weird." He rubs the back of his neck. "Are we, Barry? We're not acting weird. We're acting normal. Totally normal."

The dark look that Barry fixes on Len finally ends his unusually hyper rambling.

"That," Cisco says. "That's what I'm talking about. Is it opposite day and no one told me? Should I be skulking around directing my inner rage at everyone who doesn't deserve it and randomly rambling off Spanish in the middle of sentences without bothering to translate for my colleagues who don't speak the language?"

"Yes?" Len says.

Barry heaves a sigh, leans against the computer desk, and begins to inspect his nails. He's the picture of disaffection, so either it is opposite day or something happened overnight to swap their personalities.

"Staff meeting," Caitlin says briskly. She appears in the cortex for just a minute and waves at them to get into the conference room. "You're a minute late and Hartley is already preparing a tirade."

Caitlin and Cisco head into the glass-walled conference room ahead of Barry and Len, who hang back and continue the whispered conversation Cisco had interrupted a few minutes before.

"We can't tell Cisco."

"It's not going to wear off on its own. He built the device. He'll know how to reverse it."

"We'll figure out how to reverse it on our own. We're engineers too."

"Not mechanical engineers."

Dr. Wells' voice cuts through their conversation, and reluctantly they takes their usual seats around the conference room table.

"Now that we're all here ...," Dr. Wells says, with a touch of annoyance in his voice. He closes the conference room door with a snap and strides across the room to take his customary place at the head of the table. "The Mayor has left me another three voicemails demanding answers. Please tell me we have some. Barry, what do you have?"

Barry opens his mouth to begin briefing everyone on the compounds he's been creating in his lab that might have a power-neutralizing effect on metahumans, but then he remembers that he's not exactly himself today. Len flashes him a mischievous smirk that looks so wrong on Barry's lips, then he launches into a caricature of Barry's excited way of speaking.

"Yeah, yeah, yeah. So, okay. I've been working on this super cool new serum that will cancel out any meta's powers, provided we can actually, you know, get close enough to jam a needle in their neck. Which, I mean, you know, it's a little far-fetched, I guess, because how are any of us going to get that close to Weather Wizard, right? Anyway, but yeah, that's what I've been doing."

The other department heads around the table exchange curious looks, and no wonder, because just last week Barry had promised them this was the best possible way to dampen meta powers without any long term damage to the meta. Obviously, Len hadn't agreed.

"Do you have any specifics for us, Mr. Allen?" Dr. Wells asks. His patience is wearing pretty thin. It's not a surprise, really, with city officials breathing down his neck about cleaning up the mess his particle accelerator made and STAR Labs being just as clueless as everyone else about how to fix their mistake.

"Oh, yeah. It's potassium dioxide."

Barry wants to bang his head against the desk. Caitlin's brow furrows in confusion, but she tries to make sense of potassium dioxide - which any chemical engineer worth their salt would call potassium superoxide anyway - as a component of the serum.

"So ... you think we need to introduce inorganic elements or ... potassium dioxide on its own ... or ... Barry, what are you talking about?"

"Barry's having an off day," Barry says. "He ... hit his head on some ice in the parking lot."

Caitlin instantly begins to fuss over Len, asking him to name the President and his home address - which Barry is surprised Len knows - and what day it is. Convinced his top chemical engineer doesn't need immediate attention from a neurosurgeon, Dr. Wells continues the meeting while Caitlin does a physical examination.

"Len, why don't you update us on your projects?"

Across the table, Len swats Caitlin's hands away from his head. Len has never worn the deer-in-the-headlights look that is plastered all over his face now, and it's not becoming. He kicks Barry under the table, prompting him to say something. Anything.

"Lightning," Barry blurts. "I'm doing experiments with lightning."

"And keys?" Hartley quips. "If we're all lucky, our electrical engineering department might discover electricity soon."

Len regrets prompting Barry to speak. Wells looks like he regrets his entire life, particularly the days where he hired Barry and Len. Hartley saves them all by taking it upon himself to give actual updates on his projects to the group, and unlike "the inanity they've had to deal with this morning" - Hartley's precise words - they sound feasible and promising.

After the meeting, Barry drags Len through the corridors to the chemical engineering lab.

"When is this going to wear off?" Barry demands. " _How_ is this going to wear off?"

"Let's recreate the circumstances," Len quips.

Barry glares at him.

"Aren't you curious about how I feel when we're together?"

Barry glares at him harder.

"Look, Cisco said he had a meeting with Detective West this morning so he's probably not in his lab. Let's go play with his doohickey again and see if we can make it work."

The mechanical engineering lab is empty so they cross the space and examine the device on Cisco's worktable. It's still where they left it last night, sitting toward the back of the table halfway covered with a dropcloth like everyone has forgotten it's there and thrown detritus on top of it. (Hence, why Barry and Len hadn't noticed it before touching it last night.)

Nothing happens when they both touch the device. Or when Barry touches the device and Len touches Barry. Or the other way around. Barry collapses onto a stool and drops his head onto the cool metal surface of the table.

"We have to ask Cisco for help," Barry says, his voice muffled by the table. "And tell him the truth about how it happened. Oh God."

"Ashamed?" Len asks.

He sounds bored, and when Barry pops up from the table, Len is examining Barry's nails again.

"That I wanted you so badly I had sex in the first empty room I found, even after I realized it was my best friend's office? Yes." Len's gaze flicks up to Barry. It's guarded, but neither angry nor cold. "Also, I'm worried that Dr. Wells will find out we touched Cisco's inventions and put security cameras in all the labs and we won't have anywhere to be together anymore."

Len shifts his attention back to Barry's nails. He says with that same bored tone, "I have a house."

Barry draws in a sharp breath, then glances at the ground, grins at Len's shoes, and rubs the back of his neck.

"Yeah," Barry says. "Okay. Um, yeah. We should, uh, we should wait for Cisco."

Len's expression is sly, but bright. "Didn't know that blush was such a pretty color on me."

A matching expression curls in the corner of Barry's mouth. "I did."


End file.
